Intraluminal Pressure Predictor for Fluid Management System

This application claims the benefit of U.S. Provisional Application No. 63/640,377, filed Apr. 30, 2024, the disclosure of which is incorporated herein by reference in its entirety.

The disclosure generally relates to a fluid management system and particularly, but not exclusively, to a system and method for stopping a pump in the fluid management system in a manner and time to mitigate overshooting an intraluminal pressure threshold.

Flexible ureteroscopy (fURS), gynecology, and other endoscopic procedures require the circulation of fluid for several reasons. Fluid management systems may be used to deliver fluid to an anatomical cite from a reservoir at a desired pressure and/or flow rate via a peristaltic or roller pump. The fluid management system may utilize a fluid tubing set installed with a pump console to provide the fluid to the patient, often via a procedural device. Further, the fluid management system may adjust the flow rate and/or pressure at which fluid is delivered from the reservoir based on data collected from the procedural device, such as, but not limited to, pressure readings. There is an ongoing need to provide alternative configurations of the components of fluid management systems, to facilitate the use thereof.

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to necessarily identify key features or essential features of the claimed subject matter, nor is it intended as an aid in determining the scope of the claimed subject matter.

As noted, a fluid management system (FMS) can be utilized to deliver fluid to a procedure site (e.g., the urinary system, or the like) during a ureteroscopy procedure. When used in conjunction with certain procedural devices (e.g., LithoVue™ Elite, or the like), the FMS can measure the intraluminal pressure (ILP) and stop the pump if the ILP exceeds a chosen threshold. However, after disabling the pump, due for example, to the length of the fluid tubing set, fluid may continue to flow from the FMS to the procedure site, which can cause the ILP to continue to increase, even after the pump has stopped.

Further, the characteristics of the fluid outflow from the procedure site (e.g., a kidney, or the like) can cause ILP to continue to rise even after the pump has stopped. In either or both these examples, the ILP may increase past, and exceed, the threshold despite stopping the pump.

As another example, due to the capacity of the FMS to store fluid, the effects of the FMS pump speed (either increase or decrease) on ILP will not be measurable by sensors in the lumen for some amount of time (e.g., several seconds, or the like).

Additionally, an often-used feature of FMS is to aid clearing the visual field with fluid flow. To make this a responsive feature, for example, usable by a physician in real-time or on-demand, the pump of the FMS is often operated at a highly elevated speed (referred to as “boost”) when this feature is requested.

As a result of the above-described continued flow of fluid after disabling the pump, fluid dynamics related to FMS fluid supply, measurement delay, and operation of the FMS pump at boost speeds, techniques are needed to determine how to operate the pump and under what parameters such that ILP does not exceed a specified threshold. The present disclosure is directed towards identifying parameters for the pump of an FMS system that will mitigate or reduce the risk that the ILP (e.g., as measured by a procedural device) will exceed a threshold ILP value.

In some embodiments, the disclosure can be implemented as a method for a controller of a fluid management system (FMS) where the FMS is configured to provide fluid flow to an endoscopic medical device. The method can comprise receiving, at circuitry of the controller, an indication to operate a pump of the FMS at a specified parameter; determining, by the circuitry, a predicted intraluminal pressure (ILP) of a lumen at a time step in the future, wherein the endoscopic medical device comprises an elongated shaft inserted into the lumen and is configured to provide fluid from the FMS to the lumen; determining, by the circuitry, whether the predicted ILP is less than or equal to a threshold ILP level; and sending, responsive to a determination that the predicted ILP is not less than or equal to the threshold ILP level, a first control signal to the pump from the circuitry, the first control signal to cause the pump to operate at a parameter different than the specified parameter; or sending, responsive to a determination that the predicted ILP is less than or equal to the threshold ILP level, a second control signal to the pump from the circuitry, the second control signal to cause the pump to operate at the specified parameter.

With some embodiments of the method, the specified parameter comprises a desired RPM and the first control signal is configured to cause the pump to operate at an RPM different than the desired RPM.

With some embodiments of the method, the first control signal is configured to cause the pump to stop or to reverse flow direction.

With some embodiments, the method further comprises receiving, at the circuitry, an indication to operate the pump at a specified RPM, the first control signal is configured to cause the pump to operate at an RPM less than the specified RPM, and the second control signal is configured to cause the pump to operate at the specified RPM.

With some embodiments, the method further comprises receiving, at the circuitry from the pump, an indication of a current RPM of the pump; and determining, by the circuitry, the predicted ILP of the lumen at the time step in the future based in part on the current RPM of the pump and the specified RPM.

With some embodiments, the method further comprises receiving, at the circuitry from a medical device pressure sensor disposed in a distal end of the elongate shaft, an indication of a current ILP of the lumen; and determining, by the circuitry, the predicted ILP of the lumen at the time step in the future based in part on the current ILP of the lumen, the current RPM of the pump, and the specified RPM.

With some embodiments of the method, the FMS comprises a console configured to receive a fluid cassette, the pump, and an FMS pressure sensor configured to measure a pressure in the fluid cassette, and the pump is configured to cause fluid to flow through the fluid cassette, the method further comprising receiving, at the circuitry from the FMS pressure sensor, an indication of a current pressure of the fluid cassette; and determining, by the circuitry, the predicted ILP of the lumen at the time step in the future based in part on the current pressure of the fluid cassette, the current ILP of the lumen, the current RPM of the pump, and the specified RPM.

With some embodiments of the method, the fluid cassette comprises a housing defining a fluid pathway therethrough, the fluid pathway comprises a fluid dampening chamber having a fluid inlet configured for fluid ingress into the fluid dampening chamber and a fluid outlet configured for fluid egress from the fluid dampening chamber, the method further comprising determining, by the circuitry, the predicted ILP of the lumen at the time step in the future based in part on fluid dynamics of the fluid dampening chamber.

With some embodiments, the method further comprises solving, by the circuitry, a series of time-dependent differential equations; and determining, by the circuitry, the predicted ILP of the lumen at the time step in the future based on the solution to the series of time-dependent differential equations.

With some embodiments, the method further comprises solving, by the circuitry, the series of time-dependent differential equations using a forward-Euler algorithm or a backward-Euler algorithm.

With some embodiments of the method, the series of time-dependent differential equations relates a volume of the fluid cassette with the current ILP.

With some embodiments of the method, the series of time-dependent differential equations relates fluid outflow resistance of the lumen to fluid inflow resistance of the lumen.

With some embodiments of the method, the series of time-dependent differential equations is based in part on compliance of the lumen.

In some embodiments, the disclosure can be implemented as an apparatus to control a fluid management system (FMS) configured to provide fluid flow to an endoscopic medical device. The apparatus can comprise a processor coupled to a memory comprising instructions executable by the processor. The instructions when executed by the processor cause the apparatus to implement any of the method described herein.

In some embodiments, the disclosure can be implemented as at least one machine readable storage device. The at least one machine readable storage device comprising a plurality of instructions executable by circuitry of a controller for a fluid management system (FMS) configured to provide fluid flow to an endoscopic medical device cause the controller to implement any of the methods described herein.

In some embodiments, the disclosure can be implemented as a fluid management system (FMS) configured to provide fluid flow to an endoscopic medical device. The FMS can comprise a console configured to receive a fluid cassette, wherein the fluid cassette comprises a housing defining a fluid pathway therethrough, inflow tubing extending from the housing, the inflow tubing configured to couple to a source of fluid, and outflow tubing extending from the housing, the outflow tubing configured to couple to an endoscopic medical device, and the endoscopic medical device comprising an elongated shaft inserted into a lumen and configured to provide fluid from the outflow tubing to the lumen; a pump disposed in the console, the pump is configured to cause fluid to flow from the source of fluid through the fluid pathway; processing circuitry coupled to the pump; and memory coupled to the processing circuitry. The memory can store instructions that when executed by the processing circuitry cause the processing circuitry to receive an indication to operate the pump at a specified parameter, determine a predicted intraluminal pressure (ILP) of the lumen at a time step in the future, determine whether the predicted ILP is less than or equal to a threshold ILP level, and send, responsive to a determination that the predicted ILP is not less than or equal to the threshold ILP level, a first control signal to the pump, the first control signal to cause the pump to operate at a parameter different than the specified parameter, or send, responsive to a determination that the predicted ILP is less than or equal to the threshold ILP level, a second control signal to the pump, the second control signal to cause the pump to operate at the specified parameter.

With some embodiments of the FMS, the first control signal is configured to cause the pump to operate at a different RPM, to stop, or to reverse flow direction.

With some embodiments of the FMS, the memory can further store instructions, which when executed by the processing circuitry to receive the indication to operate the pump at the specified parameter, cause the processing circuitry to receive an indication to operate the pump at a specified RPM, wherein the first control signal is configured to cause the pump to operate at an RPM less than the specified RPM, and wherein the second control signal is configured to cause the pump to operate at the specified RPM.

With some embodiments of the FMS, the memory can further store instructions, which when executed by the processing circuitry, cause the processing circuitry to receive, from the pump, an indication of a current RPM of the pump; and determine the predicted ILP of the lumen at the time step in the future based in part on the current RPM of the pump and the specified RPM.

With some embodiments of the FMS, the memory can further store instructions, which when executed by the processing circuitry cause the processing circuitry to receive, from a medical device pressure sensor disposed in a distal end of the elongate shaft, an indication of a current ILP of the lumen; and determine the predicted ILP of the lumen at the time step in the future based in part on the current ILP of the lumen, the current RPM of the pump, and the specified RPM.

With some embodiments of the FMS, the console can comprise an FMS pressure sensor configured to measure a pressure in the fluid cassette, the memory can further store instructions, which when executed by the processing circuitry cause the processing circuitry to receive, from the FMS pressure sensor, an indication of a current pressure of the fluid cassette; and determine the predicted ILP of the lumen at the time step in the future based in part on the current pressure of the fluid cassette, the current ILP of the lumen, the current RPM of the pump, and the specified RPM.

With some embodiments of the FMS, the fluid pathway includes a fluid dampening chamber having a fluid inlet configured for fluid ingress into the fluid dampening chamber and a fluid outlet configured for fluid egress from the fluid dampening chamber, the memory further storing instructions, which when executed by the processing circuitry cause the processing circuitry to determine the predicted ILP of the lumen at the time step in the future based in part on fluid dynamics of the fluid dampening chamber.

In some embodiments, the disclosure can be implemented as a controller for a fluid management system (FMS) configured to provide fluid flow to an endoscopic medical device. The controller can comprise a memory storage device comprising instructions; and processing circuitry coupled to the memory and configured to receive an indication to operate a pump of the FMS at a specified parameter; determine a predicted intraluminal pressure (ILP) of a lumen at a time step in the future, wherein the endoscopic medical device comprises an elongated shaft inserted into the lumen and is configured to provide fluid from the FMS to the lumen; determine whether the predicted ILP is less than or equal to a threshold ILP level; and send, responsive to a determination that the predicted ILP is not less than or equal to the threshold ILP level, a first control signal to the pump, the first control signal to cause the pump to operate at a parameter different than the specified parameter; or send, responsive to a determination that the predicted ILP is less than or equal to the threshold ILP level, a second control signal to the pump, the second control signal to cause the pump to operate at the specified parameter.

With some embodiments of the controller, the memory storage device can further store instructions, which when executed by the processing circuitry cause the processing circuitry to solve a series of time-dependent differential equations; and determine the predicted ILP of the lumen at the time step in the future based on the solution to the series of time-dependent differential equations.

With some embodiments of the controller, the memory storage device can further store instructions, which when executed by the processing circuitry cause the processing circuitry to solve the series of time-dependent differential equations using a forward-Euler algorithm or a backward-Euler algorithm.

With some embodiments of the controller, the series of time-dependent differential equations relates a volume of the fluid cassette with the current ILP, relates fluid outflow resistance of the lumen to fluid inflow resistance of the lumen, and/or is based in part on compliance of the lumen.

The foregoing has broadly outlined the features and technical advantages of the present disclosure such that the following detailed description of the disclosure may be better understood. It is to be appreciated by those skilled in the art that the embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. The novel features of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

Some fluid management systems (FMS) for use in flexible ureteroscopy (fURS) procedures (e.g., ureteroscopy, percutaneous nephrolithotomy (PCNL), benign prostatic hyperplasia (BPH), transurethral resection of the prostate (TURP), etc.), gynecology, and other endoscopic procedures may regulate body cavity pressure when used in conjunction with an endoscope device such as, but not limited to, a LithoVue™ endoscope. The FMS can use pressure and/or temperature data from the endoscope or other endoscopic devices to adjust fluid flow and therefore regular pressure in the body cavity (e.g., intraluminal pressure (ILP)).

Direct regulation of ILP during a medical procedure may allow the fluid management system to safely drive system pressures of up to 600 mmHg to ensure no loss of flow during the procedure when tools are inserted into the working channel of the endoscope device. In some procedures, blood and/or debris may be present in the body cavity, which may negatively affect image quality through the endoscopic device. Fluid flow (e.g., irrigation) through the endoscopic device may be used to flush the body cavity to improve image quality. In some procedures, the body cavity may be relatively small and irrigation fluid may flow continuously, which can raise ILP and/or system pressure (e.g., fluid pressure within the fluid management system itself). As the volume of some cavities is very small and the irrigation fluid is continuously flowing into the cavity, the flow of fluid can cause high pressures in the cavity. Increased ILP and/or system pressure may pose risks to the patient under some circumstances.

As noted, the present disclosure is directed to adjusting operation of the pump of an FMS prior to the ILP reaching a threshold limit to mitigate the risk or likelihood that the ILP will exceed the threshold limit. Accordingly, an example FMS is described to provide clarity in understanding the claimed embodiments.illustrates an example fluid management system (FMS)that may be used in an endoscopic procedure, such as fURS procedures whileillustrates a fluid cassette that can be inserted into and/or used with the FMSto provide a flow of fluid to an endoscopic tool.toillustrates examples of the fluid cassette in various details.

Turning to, a schematic view of an FMSthat may be used in an endoscopic procedure, such as fURS procedures is shown. The FMSmay be coupled to a medical device (not shown), such as an endoscope, that allows flow of fluid therethrough. In some instances, as detailed more fulling herein, the endoscope may include a pressure sensor to provide ILP feedback to the FMS. For example, the Litho Vue™ Elite endoscope includes a pressure sensor.

The FMSincludes a fluid management unit or consoleincluding a controllerhoused within a housingof the console. In some instances, the consolemay be portable and/or mobile such that the consolemay be moved as desired. For instance, the consolemay be mounted on a wheeled cart. For example, the wheeled cartmay include a poleextending upward from a base. The basemay include a plurality of wheels(e.g., caster wheels, or the like), allowing the cartto be wheeled around to a desired location. In other instances, the consolemay be provided with another form of cart, configured to be positioned on a flat surface, mounted to a wall, etc.

The FMSmay also include touch screenincluding a displayand may further include switches or knobs in addition to touch capabilities. The touch screenallows the user to input/adjust various functions of the FMSsuch as, for example flow rate, pressure, and/or temperature. The user may also configure parameters and alarms (such as, but not limited to, a max pressure alarm, an ILP pressure alarm), information to be displayed, and the procedure mode. The touch screenallows the user to add, change, and/or discontinue the use of various modular systems within the FMS. The touch screenmay also be used to change the FMSbetween automatic and manual modes for various procedures. It is contemplated that other systems configured to receive user input may be used in place of or in addition to the touch screen, such as, but not limited to, voice commands.

The touch screenmay be configured to display, via display, a graphical user interface with selectable areas like buttons and/or may provide a functionality like physical buttons as would be understood by those skilled in the art. The displaymay be configured to show icons related to modular systems and devices included in the FMS. The displaymay also include graphical and/or textual indications of a fluid flow rate and/or fluid pressure. In some embodiments, operating parameters may be adjusted by touching a corresponding portion of the touch screen. The touch screenmay also display visual alerts and/or audio alarms if parameters (e.g., flow rate, temperature, etc.) are above or below predetermined thresholds and/or ranges. In some embodiments, the FMSmay also include further user interface components such as an optional foot pedal, a fluid warmer user interface, a fluid control interface, or other device to manually control various modular systems. For example, an optional foot pedal may be used to manually control flow rate.

The touch screenmay be operatively connected to or a part of the controller. The controllerincludes at least processing circuitry and memory storing instructions that when executed by the processing circuitry, cause the controllerto behave as outlined herein. In some embodiments, the controllercan be a tablet computer, or other computing device. The controllermay be operatively connected to one or more system components such as, for example, an inflow pump, a fluid warming system, and a fluid deficit management system. In some embodiments, these features may be integrated into a single unit. The controlleris capable of and configured to perform various functions such as calculation, control, computation, display, etc.

The controlleris also capable of tracking and storing data pertaining to the operations of the FMSand each component thereof. In some embodiments, the controllermay include wired and/or wireless network communication capabilities, such as ethernet or WIFI, through which the controllermay be connected to, for example, a local area network. The controllermay also receive signals from one or more of the sensors of the FMS. In some embodiments, the controllermay communicate with databases for best practice suggestions and the maintenance of patient records which may be displayed to the user on the display.

The fluid flow rate or the fluid pressure of fluid provided by the FMSat any given time may be displayed on the displayto allow the operating room (OR) visibility for any changes. If the OR personnel notice a change in fluid flow rate or fluid pressure that is either too high or too low, the user may manually adjust the fluid flow rate or the fluid pressure back to a preferred level. The FMSmay also monitor and automatically adjust the fluid flow rate, or the fluid pressure based on previously set parameters, as discussed herein.

An illustrative consolemay include one or more fluid container supports, such as fluid supply source hangers, each of which may support a fluid supply source (e.g., fluid bag). In some embodiments, placement and/or weight of the fluid supply source(s) hanging from the fluid supply source hangersmay be detected using a remote sensor and/or a supply load cell associated with and/or operatively coupled to each fluid supply source hangerand/or fluid container support. The controllermay be in electronic communication with the supply load cell. The fluid supply source hangersmay be configured to receive a variety of sizes of the first fluid supply source(s) such as, for example, 1 liter (L) to 5 L fluid bags (e.g., saline bags). It will be understood that any number of fluid supply sources may be used. The fluid supply source hangersmay extend from the housingof the consoleand may include one or more hooks from which one or more fluid supply sources may be suspended. In some embodiments, the fluid used in the fluid management unit may be 0.9% saline. However, it will be understood that a variety of other fluids of varying viscosities, concentrations, mixtures, and/or consistencies may be used depending on the procedure.

Turning to, the consolealong with a fluid tubing setconfigured to be coupled to a medical device (e.g., an endoscope, or the like) is depicted. As shown, the consolemay include a doorhingedly attached to the housing. The doormay be opened to access a receptacleconfigured to receive a fluid cassetteof the fluid tubing settherein. In some examples, the fluid tubing setis a single use medical device. The FMSmay include an inflow pumpconfigured to operatively engage the fluid tubing setto pump and/or transfer fluid from a fluid supply source (e.g., a fluid bag, etc.) through the fluid tubing setto a treatment site during a medical procedure. For example, the inflow pumpmay be a roller pump or peristaltic pump positioned in the receptacleconfigured to engage a length of flexible pump tubingof the fluid cassettewhen inserted therein. The doormay include an occlusion bedmounted on the interior surface of the door. The occlusion bedis configured to engage the length of flexible pump tubingof the fluid cassettewhen the dooris closed, to compress the length of flexible pump tubingbetween the occlusion bedand the inflow pump. The occlusion bedmay include a concave surface configured to engage the length of flexible pump tubing, which extends in an arcuate path around the inflow pump.

The inflow pumpmay be electrically driven and may receive power from a line source such as a wall outlet, an external or internal electrical storage device such as a disposable or rechargeable battery, and/or an internal power supply. The inflow pumpmay operate at any desired speed sufficient to deliver fluid at a desired pressure such as, for example, 5 mmHg to 50 mmHg, and/or at a target fluid flow rate or a target fluid pressure. As noted herein, the inflow pumpmay be automatically adjusted based on, for example, pressure and/or temperature readings within the treatment site and/or visual feedback from the medical device attached thereto and inserted into the treatment site.

In some embodiments, the controllermay be configured to control the inflow pumpto maintain a target fluid flow rate or target fluid pressure based on a set of system operating parameters. Further, the controllercan be configured to control the inflow pumpto prevent the ILP from exceeding a selected threshold. With some embodiments, this can include identifying a prediction of the ILP reaching the selected threshold and stopping, reversing, or otherwise adjusting operation of the pump to prevent the ILP from exceeding the threshold value even after the pump stops.